1. Technical Field
The invention relates to a light source integrated photoelectric conversion apparatus.
2. Related Art
In the past, image sensors using a photoelectric conversion element such as a photodiode have been proposed (see, for example, JP-A-11-121731). An image sensor disclosed in JP-A-11-121731 has a structure where a plurality of pixels is disposed in a matrix shape. Each of a plurality of pixels is provided with the photodiodes. Optical signals detected by a plurality of photodiodes can be read out for each photodiode by a matrix circuit.
In order to read patterns of a reading object exactly in the image sensor, it is important to uniformly illuminate the reading object with high illuminance. This is because, the higher the intensity of light reflected on the surface of the reading object becomes, the more easily this light is detected by the photodiode.
As an image sensor including thin-film light-emitting elements which illuminate the reading object, Japanese Patent No. 3,561,302 has proposed a light source integrated solid-state imaging device. The light source integrated solid-state imaging device disclosed in Japanese Patent No. 3,561,302 has a structure where a pair of substrates is bonded by a transparent body. A plurality of solid-state imaging elements constituted by phototransistors, and a reading drive circuit of the solid-state imaging elements are formed on one of the substrates. Electroluminescence films are formed on the other substrate.
Using the technique of Japanese Patent No. 3,561,302 allows the object such as a document to be illuminated by the light emitted from the electroluminescence film. Therefore, it is contemplated that the intensity of light reflected on a document is secured, to thereby allow the document to be exactly read by the solid-state imaging element. However, in the technique of Japanese Patent No. 3,561,302, from the perspective of enhancing resolution and thinning of an apparatus, there are points needing improvement.
In the technique of Japanese Patent No. 3,561,302, since a pair of substrates is bonded by a transparent body, it is difficult to achieve thinning of an apparatus due to the thickness of the substrate or the thickness of the transparent body. Further, in a process bonding a pair of substrates, high accurate aligning technique is required, and thereby the cost of manufacturing may be increased. Supposing the aligning accuracy of a pair of substrates is lacking, a portion of pixels is overlapped with the electroluminescence element, to thereby become nonfunctional. In addition, supposing the margin for positional deviation is increased, there may be a possibility of causing disadvantages that the pixel size becomes smaller by the increased margin and sensitivity becomes low, or the number of pixels becomes small and the resolution becomes low.